Changing Shells on a Virtual Machine with RHEL 6 installed

Hello,

I have Red Hat Linux (CentOS) installed on a virtual machine with software already installed.

I want to install something that uses CSHELL as opposed to the BASH Shell my CentOS already has.

Is it possible to change the shell I use ? Will this affect the software already installed ? Will it have to be installed again ? Will it not work ? Can I just change the shell to C Shell with no effects ?